Linear actuators are used to move an object along a straight line, either between two end points or to a defined position. Linear electro-mechanical actuators typically incorporate a rotating electrical motor and some kind of mechanical transmission module to convert the relatively high-speed rotation of the motor to a low speed linear motion. This transmission module may incorporate a gear box and/or a screw shaft.
Linear electro-mechanical actuators are constructed to perform many thousands to hundreds of thousands, or more, strokes (i.e. movements of the object along the straight line) over relatively long travel distances. Upon use, surfaces of the linear actuators are thus subjected to stressing loads, such as rotational, radial and/or axial forces, which may throw off and/or scrape off lubricants being applied to these surfaces. Consequently, these surfaces require continuous relubrication in order to ensure a long service life of the linear actuators.
Today, relubrication is a troublesome operation and often large amounts of lubricants are wasted due to unprecise application with regard to both the location in the actuator and the amount of lubricants applied. Hence, there is a need in the art for more efficient lubrication of linear electro-mechanical actuators.